The commander of a Bay Area National Guard unit is accused of taking nude photos of female subordinates in a shower at Baghdad's Abu Ghraib prison, where allegations of abuse of Iraqi inmates has focused attention on a place some troops described as chaotic.

Most of the 124 members of the 870th Military Police Company, based in Pittsburg, returned from Iraq on Easter Sunday after nearly a year's duty. But Leo Merck, a 32-year-old financial analyst from Fremont, remained in Kuwait facing court-martial on charges that he took the photos and downloaded them onto his computer.

Merck faced charges of conduct unbecoming an officer and unauthorized use of a government computer for his alleged actions in November, according to an Army report on abuse of Iraqi inmates at Abu Ghraib.

The California National Guard confirmed the investigation Wednesday but referred inquiries to Army officials in Kuwait, who could not be reached. Merck's status and whereabouts were unclear, and a woman who answered the phone at a family home in Minot, N.D., declined to comment.

Merck's unit worked primarily in the towers and entry points at the sprawling prison and has not been implicated in the abuse scandal. Merck, a senior financial analyst at KLA-Tencor Corp. of San Jose before his deployment, was relieved of command.

Spc. Myrna Hernandez, 26, of Antioch, told The Chronicle she had been sitting, clothed, inside a portable plywood shower Nov. 12 talking with two female soldiers in her unit who were showering.

"I saw someone get on their knees ... and they had a camera in their hand, " Hernandez said.

She rushed to identify the person, slipped and landed with a view of the photographer, she said.

"I saw his face, and it was the commander," Hernandez said.

Hernandez said she and the two other women -- there were six in the unit -- had discussed the incident and gone to a chaplain, who initiated a Judge Advocate General investigation. Hernandez said that she had later been shown five pictures that investigators said were among 15 found on Merck's computer. Three of the five pictures were nude shots of a woman in Merck's unit, Hernandez said.

"I was just in shock," she said of the incident. "I couldn't believe it."

Another soldier in the unit, Sgt. Denis Ensminger, 40, of Alameda, said members of the 870th were stunned by the investigation. He said he was perplexed, because Hernandez is honest, and Merck is a "professional soldier and a good company commander."

Ensminger said Merck had saved lives when, in September, he negotiated the peaceful end to a large demonstration outside city offices in Karbala, where the 870th was stationed before being sent to Abu Ghraib in October. Several hundred Iraqis armed with swords and other weapons were angry that military police had confiscated weapons from a local religious leader's bodyguards, Ensminger said. Things grew so tense that soldiers affixed bayonets to their guns, he said.

"It was close," Ensminger said. "Leo Merck brought a peaceful conclusion to the situation. Now, no one will remember that, and that's sad."

Spc. Jory Preston, 31, of Walnut Creek, said he was unaware of the Merck investigation or of the alleged abuse of prisoners. He said duty at Abu Ghraib was difficult because officers were overworked and understaffed. Preston said he and others worked 12 hours a day, seven days a week, with no time off.

Further hindering morale, he said, was limited use of telephones and the Internet and mail that came three to four weeks late. Still, he said, the assignment "wasn't as bad as everyone thinks it was."

Spc. Dave Bischel of Rodeo said he had spent nearly a year in Iraq -- five months at Abu Ghraib -- and felt increasingly stressed as his tour kept being extended. He was initially assigned to force protection, monitoring checkpoints and perimeter security.

"But then one of the MPs got caught shooting inmates with a slingshot, and I replaced her," Bischel recalled. "I spent some time down there with the inmates. It's a stressful thing. There's always the threat of riot."

Soldiers routinely cursed at prisoners, who learned to return the insults in English. The prison also was attacked by rockets, rocket-propelled grenades and mortars on several occasions, he said.

Morale was so bad that a combat stress management team prescribed the antidepressants Prozac and Paxil to troops, soldiers said.

"I saw quite a few soldiers just lose it," Bischel said. "They'd start yelling and freaking out and throwing things."